Introduce minimal OOBE test as reference for startup time measuement

Bug: 1058022
Change-Id: I289c91d03ae7e1ac6c3e47224e5ea890b64e94a4
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2093483
Auto-Submit: Denis Kuznetsov [CET] <antrim@chromium.org>
Commit-Queue: Roman Aleksandrov <raleksandrov@google.com>
Reviewed-by: Roman Aleksandrov <raleksandrov@google.com>
Cr-Commit-Position: refs/heads/master@{#748307}

chrome/browser/chromeos/login/screens/welcome_screen_browsertest.cc

@@ -185,6 +185,14 @@ IN_PROC_BROWSER_TEST_F(WelcomeScreenBrowserTest, WelcomeScreenElements) {
       {"connect", "welcomeScreen", "enableDebuggingLink"});
 }
 
+// This is a minimal possible test for OOBE. It is used as reference test
+// for measurements during OOBE speedup work.
+// TODO(crbug.com/1058022): Remove after speedup work.
+IN_PROC_BROWSER_TEST_F(WelcomeScreenBrowserTest, OobeStartupTime) {
+  welcome_screen_->Show();
+  OobeScreenWaiter(WelcomeView::kScreenId).Wait();
+}
+
 IN_PROC_BROWSER_TEST_F(WelcomeScreenBrowserTest, WelcomeScreenNext) {
   welcome_screen_->Show();
   OobeScreenWaiter(WelcomeView::kScreenId).Wait();